The present invention generally relates to a rotating machine, and, more particularly, to a method and apparatus to prevent water or waste migration to the bearings of the rotating machine.
The bearings are important components of many rotating machines, such as vacuum blowers used in aircraft waste systems. The pressure differential created by the rotating machine and/or the orientation of the unit as installed in the system can lead to water or waste ingestion by the bearings. The water or waste ingestion can wash the grease out of the bearings resulting in premature bearing failure. Methods of sealing bearings have been described.
In U.S. Pat. No. 6,599,020, a double seal bearing is disclosed. The described assembly includes a pair of annular inner and outer sealing plates having respective central openings with a remaining slight clearance between each respective sealing plate and one of the inner and outer races, respectively, so as to assure the labyrinth seal function. Although the described assembly may reduce water or waste ingestion, the assembly may not be suitable for all applications and can increase manufacturing complexity.
In U.S. Pat. No. 7,337,764, a method of pressure balancing across a bearing adjacent to a pressure differential is described. The method primarily includes providing a bypass port around the bearing for allowing a fluid flow from a first pressure side to a second pressure side. Although the described method may reduce the pressure differentials that can force contaminants into the bearing as well as force lubricant out of the bearing, the '764 patent lacks a method for sealing the bearings.
As can be seen, there is a need for improved an apparatus and method to prevent water or waste migration to the bearings of a rotating machine. Further, an assembly is needed that can provide improved bearing sealing.